Low white blood cells can be caused by a variety of reasons, some cases can be self-healing, such as drug-induced low white blood cells, and some cases can not be self-healing, such as low white blood cells caused by bone marrow disease. 1. Drug-induced low white blood cells: some drugs can cause low white blood cells, such as cephalosporin and other antibiotics, usually after stopping the drug, white blood cells can return to normal. 2. Infections: viral infections can also cause low white blood cells, usually with the cure of the infection, white blood cells can return to normal. Drugs include ganciclovir, etc. 3. Radiation exposure: Prolonged exposure to radiation can also cause a decrease in white blood cells, which will normally return to normal after the radiation exposure is stopped. 4. Bone marrow diseases: aplastic anemia, multiple myeloma and other bone marrow diseases can also cause low white blood cells, which cannot be cured on their own, and only when the disease is under control can the white blood cells return to normal. Low white blood cells may also be caused by other reasons, if the white blood cells continue to be lower than the normal level, you should go to the hospital in a timely manner to find out the cause and under the guidance of the physician to carry out targeted treatment.